Method
VipsImagereduce
Declaration [src]
int
vips_reduce (
VipsImage* in,
VipsImage** out,
double hshrink,
double vshrink,
...
)
Description [src]
Reduce in by a pair of factors with a pair of 1D kernels.
This will not work well for shrink factors greater than three.
Set gap to speed up reducing by having vips_shrink() to shrink
with a box filter first. The bigger gap, the closer the result
to the fair resampling. The smaller gap, the faster resizing.
The default value is 0.0 (no optimization).
This is a very low-level operation: see vips_resize() for a more
convenient way to resize images.
This operation does not change xres or yres. The image resolution needs to be updated by the application.
Optional arguments
kernel:VipsKernel, kernel to interpolate with (default:VIPS_KERNEL_LANCZOS3)gap:gdouble, reducing gap to use (default: 0.0)
See also
This method is not directly available to language bindings.
Parameters
out-
Type:
VipsImageOutput image.
The argument will be set by the function. The caller of the method takes ownership of the returned data, and is responsible for freeing it. hshrink-
Type:
doubleHorizontal shrink.
vshrink-
Type:
doubleVertical shrink.
...-
Type:
NULL-terminated list of optional named arguments.